From patchwork Wed Oct 9 08:51:27 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jean-Jacques Hiblot X-Patchwork-Id: 175607 Delivered-To: patch@linaro.org Received: by 2002:a92:7e96:0:0:0:0:0 with SMTP id q22csp463777ill; Wed, 9 Oct 2019 01:52:14 -0700 (PDT) X-Google-Smtp-Source: APXvYqwTwtrw4Ix/oGsyJa+q9OzxeFDxeUQ8cX1RjOFs7lbXtmxE2+id1kqm767ERrmPhneA9dsQ X-Received: by 2002:a17:902:820f:: with SMTP id x15mr2103687pln.288.1570611134742; Wed, 09 Oct 2019 01:52:14 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1570611134; cv=none; d=google.com; s=arc-20160816; b=gnkPjg/+CByPBFjmc/QfVICuAro+t59tI1st41B4PD4IEmsuChaNVUrZRQ3hR7ZoAN I2qSjFwN5nmVRQWxhIZgUZnZiTToH24XFh9SHwlkBW38I2YByUljsL5le8VSutKxrMsV 8JLbkIfrDJHP6N5EiCEmfMfUk0AiMKClFMQ9mCnc0bUI/Rj2cuUl2tSkscy2q5wKZH3n /AlDwsPc6ZEZzuNUGSs73SVVXbgRFXPm+fv+Jh8oRr3xpzAXAc2Fa4GHAn/AJarFuAW/ o0BSU6aUTT8V8aVG1g5n62+cct1tj8TkQY1Sgtq4VVdyAdExmxI9Iz3MCKXsA8e8XPrC DCaw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=sender:errors-to:content-transfer-encoding:cc:list-subscribe :list-help:list-post:list-archive:list-unsubscribe:list-id :precedence:mime-version:references:in-reply-to:message-id:date :subject:to:from:delivered-to; bh=Vjkcaa78WaUxo5IhrxUDXeJSyBN1pjqxChqiBcPWgV8=; b=uzoEaiqbj9Y6w1+M9/gJOYOaWoFFSiHIiSg8p/XiIlTFeNfgl4FQaCiIgEqTF2fuJB wrfW07iR2vsFdpT81etJuNHceaAnGWA/bQVAfwA3mSb+CZhPQoItJH9mPAKFb3DVmIxj YnDPL6eHn9XZcqEnryM/o2U87A2GkQ297ZU0SM0WF1sb0yoWZfLtJJgzQNghk4F0hSeS xKz5jByQYGCIEtGhD3RfzZSikCMPy6KmXTrs1+r3vEGEKr2DJ2BiIcJNIAGogLD5HvSb mXe45qGWpRD1FiUhUSyDi2upmd2xD9piUeRbyo4LW9ShGprvfnsIoJNI78Qyi1gGTkO6 t/8Q== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of dri-devel-bounces@lists.freedesktop.org designates 131.252.210.177 as permitted sender) smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org; dmarc=fail (p=QUARANTINE sp=NONE dis=QUARANTINE) header.from=ti.com Return-Path: Received: from gabe.freedesktop.org (gabe.freedesktop.org. [131.252.210.177]) by mx.google.com with ESMTPS id 126si1593617pgg.352.2019.10.09.01.52.14 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Wed, 09 Oct 2019 01:52:14 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of dri-devel-bounces@lists.freedesktop.org designates 131.252.210.177 as permitted sender) client-ip=131.252.210.177; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of dri-devel-bounces@lists.freedesktop.org designates 131.252.210.177 as permitted sender) smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org; dmarc=fail (p=QUARANTINE sp=NONE dis=QUARANTINE) header.from=ti.com Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id CD0CD6E937; Wed, 9 Oct 2019 08:52:12 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from lelv0143.ext.ti.com (lelv0143.ext.ti.com [198.47.23.248]) by gabe.freedesktop.org (Postfix) with ESMTPS id 574E16E937 for ; Wed, 9 Oct 2019 08:52:11 +0000 (UTC) Received: from lelv0266.itg.ti.com ([10.180.67.225]) by lelv0143.ext.ti.com (8.15.2/8.15.2) with ESMTP id x998q6Bm035255; Wed, 9 Oct 2019 03:52:06 -0500 Received: from DLEE104.ent.ti.com (dlee104.ent.ti.com [157.170.170.34]) by lelv0266.itg.ti.com (8.15.2/8.15.2) with ESMTPS id x998q6KF023623 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Wed, 9 Oct 2019 03:52:06 -0500 Received: from DLEE114.ent.ti.com (157.170.170.25) by DLEE104.ent.ti.com (157.170.170.34) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1713.5; Wed, 9 Oct 2019 03:52:02 -0500 Received: from lelv0327.itg.ti.com (10.180.67.183) by DLEE114.ent.ti.com (157.170.170.25) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1713.5 via Frontend Transport; Wed, 9 Oct 2019 03:52:02 -0500 Received: from localhost (ileax41-snat.itg.ti.com [10.172.224.153]) by lelv0327.itg.ti.com (8.15.2/8.15.2) with ESMTP id x998q4n1094650; Wed, 9 Oct 2019 03:52:05 -0500 From: Jean-Jacques Hiblot To: , , , , , , Subject: [PATCH v10 6/6] backlight: add led-backlight driver Date: Wed, 9 Oct 2019 10:51:27 +0200 Message-ID: <20191009085127.22843-7-jjhiblot@ti.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20191009085127.22843-1-jjhiblot@ti.com> References: <20191009085127.22843-1-jjhiblot@ti.com> MIME-Version: 1.0 X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 X-Mailman-Original-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1570611126; bh=CJRCJuf3Ec4lXKJvRu7xvfp5Qc4WB9fgDUnDZNXBBis=; h=From:To:CC:Subject:Date:In-Reply-To:References; b=J/yC1r1zlbV7N78XH+SIII9Hiszdkk1jm2UI0nmKW+fJBNRE+rJAfo+ru/SggPb91 LERUse9hRmvUZwz6UcEVlC095S+SyvGQXLAD1pvnzCGBwIzQNYpz1LNemeq1vcnuY1 s6+PaR4RVt23Uc9tVNqiINZu24FRQ/sR5lNQqBF8= X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, tomi.valkeinen@ti.com, dmurphy@ti.com, Jean-Jacques Hiblot , linux-leds@vger.kernel.org Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" From: Tomi Valkeinen This patch adds a led-backlight driver (led_bl), which is similar to pwm_bl except the driver uses a LED class driver to adjust the brightness in the HW. Multiple LEDs can be used for a single backlight. Signed-off-by: Tomi Valkeinen Signed-off-by: Jean-Jacques Hiblot Acked-by: Pavel Machek Reviewed-by: Daniel Thompson Reviewed-by: Sebastian Reichel --- drivers/video/backlight/Kconfig | 7 + drivers/video/backlight/Makefile | 1 + drivers/video/backlight/led_bl.c | 258 +++++++++++++++++++++++++++++++ 3 files changed, 266 insertions(+) create mode 100644 drivers/video/backlight/led_bl.c diff --git a/drivers/video/backlight/Kconfig b/drivers/video/backlight/Kconfig index 8b081d61773e..585a1787618c 100644 --- a/drivers/video/backlight/Kconfig +++ b/drivers/video/backlight/Kconfig @@ -458,6 +458,13 @@ config BACKLIGHT_RAVE_SP help Support for backlight control on RAVE SP device. +config BACKLIGHT_LED + tristate "Generic LED based Backlight Driver" + depends on LEDS_CLASS && OF + help + If you have a LCD backlight adjustable by LED class driver, say Y + to enable this driver. + endif # BACKLIGHT_CLASS_DEVICE endmenu diff --git a/drivers/video/backlight/Makefile b/drivers/video/backlight/Makefile index 63c507c07437..2a67642966a5 100644 --- a/drivers/video/backlight/Makefile +++ b/drivers/video/backlight/Makefile @@ -57,3 +57,4 @@ obj-$(CONFIG_BACKLIGHT_TPS65217) += tps65217_bl.o obj-$(CONFIG_BACKLIGHT_WM831X) += wm831x_bl.o obj-$(CONFIG_BACKLIGHT_ARCXCNN) += arcxcnn_bl.o obj-$(CONFIG_BACKLIGHT_RAVE_SP) += rave-sp-backlight.o +obj-$(CONFIG_BACKLIGHT_LED) += led_bl.o diff --git a/drivers/video/backlight/led_bl.c b/drivers/video/backlight/led_bl.c new file mode 100644 index 000000000000..718fa3e03eac --- /dev/null +++ b/drivers/video/backlight/led_bl.c @@ -0,0 +1,258 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2015-2019 Texas Instruments Incorporated - http://www.ti.com/ + * Authors: Tomi Valkeinen + * Jean-Jacques Hiblot + */ + +#include +#include +#include +#include + +struct led_bl_data { + struct device *dev; + struct backlight_device *bl_dev; + struct led_classdev **leds; + bool enabled; + int nb_leds; + unsigned int *levels; + unsigned int default_brightness; + unsigned int max_brightness; +}; + +static void led_bl_set_brightness(struct led_bl_data *priv, int level) +{ + int i; + int bkl_brightness; + + if (priv->levels) + bkl_brightness = priv->levels[level]; + else + bkl_brightness = level; + + for (i = 0; i < priv->nb_leds; i++) + led_set_brightness(priv->leds[i], bkl_brightness); + + priv->enabled = true; +} + +static void led_bl_power_off(struct led_bl_data *priv) +{ + int i; + + if (!priv->enabled) + return; + + for (i = 0; i < priv->nb_leds; i++) + led_set_brightness(priv->leds[i], LED_OFF); + + priv->enabled = false; +} + +static int led_bl_update_status(struct backlight_device *bl) +{ + struct led_bl_data *priv = bl_get_data(bl); + int brightness = bl->props.brightness; + + if (bl->props.power != FB_BLANK_UNBLANK || + bl->props.fb_blank != FB_BLANK_UNBLANK || + bl->props.state & BL_CORE_FBBLANK) + brightness = 0; + + if (brightness > 0) + led_bl_set_brightness(priv, brightness); + else + led_bl_power_off(priv); + + return 0; +} + +static const struct backlight_ops led_bl_ops = { + .update_status = led_bl_update_status, +}; + +static int led_bl_get_leds(struct device *dev, + struct led_bl_data *priv) +{ + int i, nb_leds, ret; + struct device_node *node = dev->of_node; + struct led_classdev **leds; + unsigned int max_brightness; + unsigned int default_brightness; + + ret = of_count_phandle_with_args(node, "leds", NULL); + if (ret < 0) { + dev_err(dev, "Unable to get led count\n"); + return -EINVAL; + } + + nb_leds = ret; + if (nb_leds < 1) { + dev_err(dev, "At least one LED must be specified!\n"); + return -EINVAL; + } + + leds = devm_kzalloc(dev, sizeof(struct led_classdev *) * nb_leds, + GFP_KERNEL); + if (!leds) + return -ENOMEM; + + for (i = 0; i < nb_leds; i++) { + leds[i] = devm_of_led_get(dev, i); + if (IS_ERR(leds[i])) + return PTR_ERR(leds[i]); + } + + /* check that the LEDs all have the same brightness range */ + max_brightness = leds[0]->max_brightness; + for (i = 1; i < nb_leds; i++) { + if (max_brightness != leds[i]->max_brightness) { + dev_err(dev, "LEDs must have identical ranges\n"); + return -EINVAL; + } + } + + /* get the default brightness from the first LED from the list */ + default_brightness = leds[0]->brightness; + + priv->nb_leds = nb_leds; + priv->leds = leds; + priv->max_brightness = max_brightness; + priv->default_brightness = default_brightness; + + return 0; +} + +static int led_bl_parse_levels(struct device *dev, + struct led_bl_data *priv) +{ + struct device_node *node = dev->of_node; + int num_levels; + u32 value; + int ret; + + if (!node) + return -ENODEV; + + num_levels = of_property_count_u32_elems(node, "brightness-levels"); + if (num_levels > 1) { + int i; + unsigned int db; + u32 *levels = NULL; + + levels = devm_kzalloc(dev, sizeof(u32) * num_levels, + GFP_KERNEL); + if (!levels) + return -ENOMEM; + + ret = of_property_read_u32_array(node, "brightness-levels", + levels, + num_levels); + if (ret < 0) + return ret; + + /* + * Try to map actual LED brightness to backlight brightness + * level + */ + db = priv->default_brightness; + for (i = 0 ; i < num_levels; i++) { + if ((i && db > levels[i-1]) && db <= levels[i]) + break; + } + priv->default_brightness = i; + priv->max_brightness = num_levels - 1; + priv->levels = levels; + } else if (num_levels >= 0) + dev_warn(dev, "Not enough levels defined\n"); + + ret = of_property_read_u32(node, "default-brightness", &value); + if (!ret && value <= priv->max_brightness) + priv->default_brightness = value; + else if (!ret && value > priv->max_brightness) + dev_warn(dev, "Invalid default brightness. Ignoring it\n"); + + return 0; +} + +static void led_bl_cleanup(void *data) +{ + struct led_bl_data *priv = data; + int i; + + led_bl_power_off(priv); + for (i = 0; i < priv->nb_leds; i++) + led_sysfs_enable(priv->leds[i]); +} + +static int led_bl_probe(struct platform_device *pdev) +{ + struct backlight_properties props; + struct led_bl_data *priv; + int ret, i; + + priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + platform_set_drvdata(pdev, priv); + + priv->dev = &pdev->dev; + + ret = led_bl_get_leds(&pdev->dev, priv); + if (ret) + return ret; + + ret = led_bl_parse_levels(&pdev->dev, priv); + if (ret < 0) { + dev_err(&pdev->dev, "Failed to parse DT data\n"); + return ret; + } + + ret = devm_add_action_or_reset(&pdev->dev, led_bl_cleanup, priv); + if (ret) + return ret; + + for (i = 0; i < priv->nb_leds; i++) + led_sysfs_disable(priv->leds[i]); + + memset(&props, 0, sizeof(struct backlight_properties)); + props.type = BACKLIGHT_RAW; + props.max_brightness = priv->max_brightness; + props.brightness = priv->default_brightness; + props.power = (priv->default_brightness > 0) ? FB_BLANK_POWERDOWN : + FB_BLANK_UNBLANK; + priv->bl_dev = devm_backlight_device_register(&pdev->dev, + dev_name(&pdev->dev), &pdev->dev, priv, &led_bl_ops, + &props); + if (IS_ERR(priv->bl_dev)) { + dev_err(&pdev->dev, "Failed to register backlight\n"); + return PTR_ERR(priv->bl_dev); + } + + backlight_update_status(priv->bl_dev); + + return 0; +} + +static const struct of_device_id led_bl_of_match[] = { + { .compatible = "led-backlight" }, + { } +}; + +MODULE_DEVICE_TABLE(of, led_bl_of_match); + +static struct platform_driver led_bl_driver = { + .driver = { + .name = "led-backlight", + .of_match_table = led_bl_of_match, + }, + .probe = led_bl_probe, +}; + +module_platform_driver(led_bl_driver); + +MODULE_DESCRIPTION("LED based Backlight Driver"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:led-backlight");